The formation of semiconductor substrates by Czochralski (CZ) processes may suffer from unreliability due to oxygen complexes formed due to oxygen interstitials. Processes for reducing the effects of oxygen complexes (e.g. by magnetic CZ processes) may lead to fluctuations in the specific resistance of the semiconductor substrates. The processes for reducing these fluctuations in specific resistance may cause a doping profile of the semiconductor substrate that leads to deterioration in the switch on behavior of semiconductor devices formed in the semiconductor substrate. The formation of semiconductor substrates by Float Zone (FZ) processes may lead to semiconductor substrates with a lower proportion of oxygen. However, FZ processes may be expensive.